1. Field of the Invention
The invention relates to a method for operating a DC-DC converter for a charger, to a DC-DC converter, and to a charger for a motor vehicle.
2. Description of the Related Art
A motor vehicle that has and uses at least one electric motor for driving or locomotion is referred to as an electric vehicle or hybrid vehicle. During travel, the at least one electric motor is to be supplied with electrical energy from at least one electrical energy store, which can also be referred to as battery or rechargeable battery. The at least one electrical energy store, in turn, is supplied with electrical energy in a charging operation. A charger on board the motor vehicle is used for this purpose. Operating parameters of the charger change during a charging operation and influence a charging operation is also influenced.
DE 26 45 507 A1 describes an electrical power converter for a rechargeable battery of an electric vehicle. The electrical power converter is designed to convert a DC voltage of the rechargeable battery into an AC voltage. This makes it possible to feed a drive motor of the electric vehicle from the rechargeable battery. The drive motor has a comparatively high voltage, while the rechargeable battery has a low voltage.
DE 44 37 876 A1 describes a method for operating an electrical power supply in an electric vehicle. The power supply comprises a first battery for an electrical vehicle drive and a second battery, chargeable via a DC-DC converter, for feeding other loads in the electric vehicle. In this case, the DC-DC converter is activated only if a load requirement made of it has reached an expedient minimum value.
U.S. Pat. No. 6,150,794 discloses a charging system for a motor-driven vehicle. The charging system has two chargers, each of which has a coil. A battery of the vehicle can be charged by the charging system if the coils of both chargers are arranged at a small distance from one another.
CN 201269922 Y discloses an automatic detection system for a battery that is designed to control its operation so that only a small amount of heat is generated.
Against this background, it is an object of the present invention to optimize an efficiency of a charger of a motor vehicle with at least one DC-DC converter.